Exchange server not accessible

I need to access mails from 2 different domains (say A and B) simultaneouly.
I always work in Domain A and want to access mails for B.

Both are using exchange server. I am using Microsoft Outlook 2002 as the client. It supports only 1 domain at a time. Thats why I created profiles.

For A outlook does not need any authentication. However for B I need to choose that profile and enter “NAME, PASSWORD, DOMAIN”.

As a solution to the above problem I downloaded some email clients that support IMAP.

They worked well for A (in which I’m logged in and usually work) but are not able to access B. The software worked when installed and tried on a machine of B.

I cant ping exchange server of B but using outlook it works.

What should I do??
Thanks
Manish